textproduct: Rapid City

KEY MESSAGES

- Strong high pressure this week will bring very hot temperatures and fire weather concerns at times.

- Isolated thunderstorms will be possible nearly each day next week. Storms may have gusty winds.

UPDATE

Issued at 1008 PM MDT Sat Jul 25 2026

It was a memorable day as both WFO UNR and KRAP broke all-time record high temperatures. See RERUNR/RERRAP for more details. Latest surface obs show widespread triple-digit heat has "cooled off" to the upper 70s to lower 90s. Another warm night is expected tonight. Some downsloping sections of the eastern foothills may struggle to reach below 80 through early Sunday morning. KUDX radar shows light showers across the area. Another upper wave across SE MT may bring overnight storms overnight, so have added low-end pops. Another round of storms is expected Sunday afternoon/evening, but CAPE will be limited given the hot/dry boundary layer. Coverage will be less than today and organized severe weather is not expected. Still, with inverted V profiles, can't rule out some storms having gusty winds. Temps tomorrow will again be well above the 100F mark...but it's not expected to be quite as hot today. With the heat combining with dewpoints of 55 to 65F tomorrow toward central SD, the Excessive Heat Warning is still in good shape. I did add Ziebach County to the warning. Heat Advisory looks good elsewhere. Will need to take a look at apparent temps on Monday to see if any headlines need to be extended.

DISCUSSION

(This Afternoon Through Friday) Issued at 1106 AM MDT Sat Jul 25 2026

Upper level ridge will remain anchored over the Rockies into the Plains supporting hot temperatures. Very hot temps the next two days as the core of the thermal ridge passes over the region. Expect temps into the 100s on most of the SD Plains and portions of the WY Plains. Heat products look good most areas, did expand the extreme heat warning west a couple zones given hotter than expected temps, with heat index readings of 105 to 110 expected there. A stronger shortwave filled with monsoon moisture will advect around the ridge in SW flow and across the FA today, supporting high based TS. Damaging winds will be possible with thunderstorms given very high based nature and resultant inverted-V profiles per drying BL. Sct wind gusts over 60 mph (possibly over 80 mph in stronger cells) will be possible given DCAPE over 2000 J/KG, esp on the SD Plains east of the Black Hills. Not much rain expected with these cells, which will support critical fire weather conds when coupled with dry fuels, downburst winds, and low RH. Things will dry out tonight, but it will remain very warm with lows in the 70s at many areas, with 80s in the BH foothills. Another hot day Sunday with dry conds most areas. The exception will be over the BH where diurnal convection will be possible and with another impulse toward the evening and overnight. Convection will be possible with this wave mainly in the western third. Expect gusty winds once again. Ridge will retrograde back west some by mid next week, supporting slightly cooler but still hot temps as highs in the 90s are expected. Isold-sct TS chances will continue as the lee trough interacts will passing impulses. Main threat from storms will be strong gusty winds given high LCL's and inverted V profiles.

AVIATION

(For the 12Z TAFS Through 12Z Monday Morning) Issued At 521 AM MDT Sun Jul 26 2026

VFR conditions are expected through the TAF period. Main aviation concerns are centered around the next round of potential thunderstorms.

Isolated thunderstorm initiation is likely around 1 to 3PM today in and around the Black Hills. Then another round of passing storms is likely late this afternoon and evening, mainly after 6PM, from storms that will develop in north-central Wyoming.

Storms today will be high based with gusty, erratic winds expected.

FIRE WEATHER

Issued At 1008 PM MDT Sat Jul 25 2026

Very hot temperatures will persist into next week as a ridge of high pressure remains over the region. This will support elevated to near critical fire weather conditions as RH's drop into the teens on the Plains each day. Winds will be marginal most days, breeziest Sunday on the SD Plains behind a trough where winds could gust to 30 mph for period. Poor recovery can also be expected most nights across portions of northeast WY, the Black Hills, and far western SD given warm overnight lows. In addition, there will be near daily chances for isolated thunderstorms as batches of mid level monsoon moisture push through the region. Storms may produce very little rainfall and gusty winds, supporting a dry lightning threat at times.

UNR WATCHES/WARNINGS/ADVISORIES

SD...Heat Advisory until 8 PM MDT this evening for SDZ001-002-012-013- 025>027-030-031-041-042-072>076-078. Extreme Heat Warning until 8 PM MDT /9 PM CDT/ this evening for SDZ014-032-043-044-046-047-049-077. WY...Heat Advisory until 8 PM MDT this evening for WYZ054>056-058>060.